Hi I recently tried to downgrade from 3.50 to 3.41, tried to numerous usb sticks numerous pup, and selfs. no attempt has succeeded any suggestions would be greatly appreciated, this is my third day of attempts and im not giving up until i succeeded
here is a copy of the notepad message i get from my ps3 after i plug in the first usb for 3mins. The green lights start blinking then and they never end.

manufacturing updating start
PackageName = /dev_usb000/PS3UPDAT.PUP
settle polling interval success
vflash is disabled...
boot from nand flash...
creating flash regions...
create storage region: (region id = 2)
format partition: (region_id = 2, CELL_FS_IOS:BUILTIN_FLSH1, CELL_FS_FAT)
create storage region: (region id = 3)
format partition: (region_id = 3, CELL_FS_IOS:BUILTIN_FLSH2, CELL_FS_FAT)
create storage region: (region id = 4)
format partition: (region_id = 4, CELL_FS_IOS:BUILTIN_FLSH3, CELL_FS_FAT)
create storage region: (region id = 5)
create storage region: (region id = 6)
Initializing
taking a while...
start Updating Proccess
Initialize elapsed time = 54 msec
check UPL
Check UPL elapsed time = 51 msec
check Package Size
get package size elapsed time = 8 msec
start Updating Package
Update packages num = 30
Update packages total size = 162260220
Update Package Revoke list
read package revoke list package (576 bytes) elapsed = 23 msec
update package revoke list elapsed = 107 msec
Update Package Revoke list done(0x8002f000)
Update Core OS Package
read core os package (5182047 bytes) elapsed = 303 msec
update core os package elapsed = 1933 msec
Update Core OS Package done(0x8002f000)
Update VSH Package
sys_memory_container_create() success(id = 0xc0effffe)
Update VSH's package : 1/22
read vsh package (1847 bytes) elapsed = 3 msec
decrypt and verify vsh package elapsed = 33 msec
write vsh package elapsed = 7056 msec
compare vsh package elapsed = 0 msec
Update VSH's package : 2/22
read vsh package (4779244 bytes) elapsed = 277 msec
decrypt and verify vsh package elapsed = 302 msec
write vsh package elapsed = 2555 msec
compare vsh package elapsed = 381 msec
Update VSH's package : 3/22
read vsh package (1927089 bytes) elapsed = 113 msec
decrypt and verify vsh package elapsed = 128 msec
write vsh package elapsed = 646 msec
compare vsh package elapsed = 142 msec
Update VSH's package : 4/22
read vsh package (5498561 bytes) elapsed = 318 msec
decrypt and verify vsh package elapsed = 341 msec
write vsh package elapsed = 3122 msec
compare vsh package elapsed = 435 msec
Update VSH's package : 5/22
read vsh package (2010269 bytes) elapsed = 121 msec
decrypt and verify vsh package elapsed = 135 msec
write vsh package elapsed = 960 msec
compare vsh package elapsed = 162 msec
Update VSH's package : 6/22
read vsh package (25242 bytes) elapsed = 11 msec
decrypt and verify vsh package elapsed = 28 msec
write vsh package elapsed = 1293 msec
compare vsh package elapsed = 8 msec
Update VSH's package : 7/22
read vsh package (7663270 bytes) elapsed = 449 msec
decrypt and verify vsh package elapsed = 391 msec
write vsh package elapsed = 13481 msec
compare vsh package elapsed = 464 msec
Update VSH's package : 8/22
read vsh package (10258879 bytes) elapsed = 599 msec
decrypt and verify vsh package elapsed = 284 msec
write vsh package elapsed = 14560 msec
compare vsh package elapsed = 518 msec
Update VSH's package : 9/22
read vsh package (8773195 bytes) elapsed = 513 msec
decrypt and verify vsh package elapsed = 240 msec
write vsh package elapsed = 6297 msec
compare vsh package elapsed = 402 msec
Update VSH's package : 10/22
read vsh package (8827678 bytes) elapsed = 519 msec
decrypt and verify vsh package elapsed = 319 msec
write vsh package elapsed = 10098 msec
compare vsh package elapsed = 488 msec
Update VSH's package : 11/22
read vsh package (6182668 bytes) elapsed = 368 msec
decrypt and verify vsh package elapsed = 204 msec
write vsh package elapsed = 2013 msec
compare vsh package elapsed = 343 msec
Update VSH's package : 12/22
read vsh package (10251215 bytes) elapsed = 601 msec
decrypt and verify vsh package elapsed = 254 msec
write vsh package elapsed = 3662 msec
compare vsh package elapsed = 455 msec
Update VSH's package : 13/22
read vsh package (10187344 bytes) elapsed = 599 msec
decrypt and verify vsh package elapsed = 260 msec
write vsh package elapsed = 5575 msec
compare vsh package elapsed = 461 msec
Update VSH's package : 14/22
read vsh package (10381187 bytes) elapsed = 613 msec
decrypt and verify vsh package elapsed = 259 msec
write vsh package elapsed = 5418 msec
compare vsh package elapsed = 471 msec
Update VSH's package : 15/22
read vsh package (9899962 bytes) elapsed = 587 msec
decrypt and verify vsh package elapsed = 259 msec
write vsh package elapsed = 6604 msec
compare vsh package elapsed = 460 msec
Update VSH's package : 16/22
read vsh package (8210627 bytes) elapsed = 489 msec
decrypt and verify vsh package elapsed = 203 msec
write vsh package elapsed = 4717 msec
compare vsh package elapsed = 381 msec
Update VSH's package : 17/22
read vsh package (10382360 bytes) elapsed = 617 msec
decrypt and verify vsh package elapsed = 265 msec
write vsh package elapsed = 6274 msec
compare vsh package elapsed = 544 msec
Update VSH's package : 18/22
read vsh package (9649989 bytes) elapsed = 573 msec
decrypt and verify vsh package elapsed = 369 msec
write vsh package elapsed = 31875 msec
compare vsh package elapsed = 835 msec
Update VSH's package : 19/22
read vsh package (7751745 bytes) elapsed = 466 msec
decrypt and verify vsh package elapsed = 351 msec
write vsh package elapsed = 23652 msec
compare vsh package elapsed = 741 msec
Update VSH's package : 20/22
read vsh package (8165430 bytes) elapsed = 490 msec
decrypt and verify vsh package elapsed = 366 msec
write vsh package elapsed = 11751 msec
compare vsh package elapsed = 682 msec
Update VSH's package : 21/22
read vsh package (8287111 bytes) elapsed = 500 msec
decrypt and verify vsh package elapsed = 347 msec
write vsh package elapsed = 19301 msec
compare vsh package elapsed = 740 msec
Update VSH's package : 22/22
read vsh package (5315230 bytes) elapsed = 330 msec
decrypt and verify vsh package elapsed = 222 msec
write vsh package elapsed = 1747 msec
compare vsh package elapsed = 363 msec
Update VSH Package done(0x8002f000)
Bul-ray Disc Player Revoke
read bdp revoke package (1905 bytes) elapsed = 24 msec
decrypt and verify bdp revoke package elapsed = 31 msec
write bdp revoke package elapsed = 2231 msec
compare bdprevoke package elapsed = 58 msec
Bul-ray Disc Player Revoke done(0x8002f000)
Update Program Revoke list
read program revoke list package (736 bytes) elapsed = 25 msec
update program revoke list elapsed = 328 msec
Update Program Revoke list done(0x8002f000)
move_2block_status_into_the_region(): region id = 3
rewrite_region() region id = 0x3, start_lba = 0x0, end_lba = 0x4000
rewrite region done (ret = 0x8002f000)
rewrite region elapsed time = 1262 msec
touch_1st_sector_in_block() region id = 0x3, start_lba = 0x0, end_lba = 0x4000
touch_1st_sector() done (ret = 0x8002f000)
touch_1st_sector() elapsed time = 1221 msec
rewrite_region() region id = 0x3, start_lba = 0x0, end_lba = 0x4000
rewrite region done (ret = 0x8002f000)
rewrite region elapsed time = 1263 msec
Update BD firmware
read BD firmware package (1966992 bytes) elapsed = 117 msec
update BD firmware elapsed = 29474 msec
Update BD firmware done(0x8002f14e)
update package elapsed time = 245279 msec
Updating or Verifying failure 0x8002f14e
UpMng.UpdatePackage() failure
manufacturing updating FAILURE(0x8002f14e)
Total Elapsed time = 247643 msec

Also this is a ps3 fat and i have already formatted the usb to fat32.